Re (2): output from udevadm

[peasthope@shaw.ca]

From:	Tom H <tomh0665@gmail.com>
Date:	Mon, 12 Jul 2010 03:43:02 -0400
>From a filesystem perspective, there is an assumed /sys "in front of" /class/...

OK, thanks.  This confirms.

joule:/home/peter# cd /sys/class/ieee1394_protocol
joule:/sys/class/ieee1394_protocol# ls -l
total 0
drwxr-xr-x 3 root root 0 2010-07-05 17:46 raw1394
drwxr-xr-x 3 root root 0 2010-07-12 07:48 video1394-0

After the camera is plugged in, the video1394 module is loaded.

peter@joule:~$ tail --lines=20 /var/log/syslog | grep 1394
Jul 12 08:53:49 joule kernel: [ 2243.967829] IEEE 1394 device has ROM CRC error
Jul 12 08:53:49 joule kernel: [ 2243.967954] ieee1394: Node added: ID:BUS[0-00:1
023]  GUID[0814436102632a2b]
Jul 12 08:53:49 joule kernel: [ 2243.969136] ieee1394: Node changed: 0-00:1023 -
> 0-01:1023
Jul 12 08:53:49 joule kernel: [ 2243.970482] IEEE 1394 device has ROM CRC error
Jul 12 08:53:50 joule kernel: [ 2244.223149] video1394: Installed video1394 modu
le
Jul 12 08:53:50 joule kernel: [ 2244.249614] ieee1394: raw1394: /dev/raw1394 dev
ice initialized

So udevadm should also tell something about /dev/video1394/0.

joule:/home/peter# udevadm info --name=/dev/video1394/0 --attribute-walk

Udevinfo starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '/class/ieee1394_protocol/video1394-0':
    KERNEL=="video1394-0"
    SUBSYSTEM=="ieee1394_protocol"
    DRIVER==""

These points in the above strike me as problematic or puzzling.
* syslog reports a ROM CRC error while the 
  camera was new & Coriander gets a live image.
* syslog reports "Node changed".
* udevadm reports an empty DRIVER.
* syslog reports a GUID but udevadm reports nothing 
  specific to the device.  An example in a Ubuntu 
  document has BUS=="usb", SYSFS{product}=="TS128MJFLASHA" 
  and many other attributes.

Any further ideas?

Thanks,         ... Peter E.



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